Latent Tuberculosis Infection (LTBI) occurs when a person is infected with the Mycobacterium tuberculosis bacteria but does not show any symptoms and is not contagious. The immune system can control the bacteria, keeping it inactive. However, LTBI can progress to active tuberculosis (TB) if the immune system weakens. Diagnosis of LTBI typically involves a tuberculin skin test or a blood test. Treatment is important to prevent the development of active TB, especially in individuals at higher risk, such as those with weakened immune systems or close contacts of TB patients.